1. Field of the Invention
This invention relates to paper transport devices for use in data printers and more particularly to a device capable of being used with margin perforated paper and with unperforated paper.
2. Prior Art
Various types of paper, for example, margin perforated fanfold paper and continuous roll paper, are utilized as the recording carrier for the written output of data and text in printers of the type employed in businesses and offices. The transport devices normally utilized for such data printers differ respectively dependent upon the type of paper employed.
For example, when margin perforated fanfold paper is utilized, transport is frequently by means of tractor drive assemblies which employ driven endless belts equipped with projecting pins which engage both sides of the paper with the pins indexing in the marginal perforations. An opposed flap may be utilized which is pivoted towards and away from the belt to maintain the margin perforations in engagement with the pins of the driving belt. Such margin perforated paper, which is normally provided in fanfold stacks, may be either single sheet or multi-sheet, and is generally used in connection with tractor drives where the tractor drive is positioned on the exit or downstream side of the print zone of the data printer.
On the other hand, continuous roll paper or unmargin perforated paper is normally moved through the data printer in a standard manner by a friction drive between a power rotated platen and opposed pin rollers acting as pinch rollers.
Change of paper has therefore normally required a change in the drive mechanism which is most frequently obtained by the expensive expedient of utilizing different data printers equipped with differing drive systems. It would therefore be an improvement in the art to provide a single data printer having a compound drive system utilizable with either margin perforated tractor driven paper or with continuous roll or non-perforated platen driven paper.